The simple act of stretching does a lot more than make you limber. It may help prevent injuries or even illness-all it takes is 10 easy minutes a day.

Why Does Flexibility Matter?
You've managed to make it to Spinning class (for the second time this week), but as soon as the instructor starts the cool down, you head for the door. Hold it right there. Turns out, stretching is just as important as getting on the bike in the first place.

Although countless studies have shown how beneficial exercise is for your body and mind (it may do everything from reducing the risk of some cancers to helping improve memory), less attention has been paid to flexibility. But doctors and physical therapists agree that it's a vital part of keeping your body fit and able. "Flexibility is the third pillar of fitness, next to cardiovascular conditioning and strength training," says David Geier, the director of sports medicine at the Medical University of South Carolina, in Charleston, and a spokesperson for the American Orthopaedic Society for Sports Medicine. In fact, flexibility can help your body reach its optimum fitness level, may play a role in injury prevention, and can even contribute to staving off conditions like arthritis and more serious illnesses.

Here's how it works: When you stretch a muscle, you lengthen the tendons, or muscle fibres, that attach it to the bone. "The longer these fibres are, the more you can increase the muscle in size when you do your strength training," says Geier. That means that a more flexible muscle has the potential to become a stronger muscle, too. In turn, building strong muscle fibres may boost your metabolism and your fitness level. Flexible muscles also make everyday activities easier on your body and may decrease your risk of certain injuries. Common behaviours, like hunching over the computer, can shorten some muscles. That, along with the natural loss of muscle elasticity that occurs with aging, can set you up so any quick or awkward motion (lunging to catch a glass before it teeters off the table, for example) could stretch your muscles beyond their limit, resulting in a strain or a tear. "Even if you're aerobically fit, it helps to be limber, too, so your body can easily adapt to physical stressors" says Margot Miller, a physical therapist in Duluth, Minnesota, and a spokesperson for the American Physical Therapy Association.

What's more, stretching may improve your circulation, increasing blood flow to your muscles. And having good circulation can help protect you against a host of illnesses, from diabetes to kidney disease. Greater flexibility has even been linked to a lower risk of cardiovascular disease. A 2009 study in the American Journal of Physiology indicated that people age 40 and older who performed well on a sit-and-reach test (a seated forward bend that measures flexibility) had less stiffness in their arterial walls, an indicator of the risk for stroke and heart attack.